Step 1: In a small bowl, warm the milk to about 105-115°F (40-46°C). Sprinkle the active dry yeast and a teaspoon of granulated sugar over the milk. Let it sit for 5-10 minutes until foamy. This confirms your yeast is active.
Step 2: In a large mixing bowl (or the bowl of a stand mixer fitted with a dough hook), combine the remaining granulated sugar, melted butter, eggs, and salt. Pour in the activated yeast mixture and mix well.
Step 3: Gradually add the all-purpose flour, about a cup at a time, mixing until a shaggy dough forms. If using a stand mixer, knead on medium-low speed for 8-10 minutes until the dough is smooth, elastic, and pulls away from the sides of the bowl. If kneading by hand, turn the dough out onto a lightly floured surface and knead for 10-15 minutes.
Step 4: Lightly grease a large bowl with oil. Place the dough in the bowl, turning it once to coat. Cover the bowl with plastic wrap or a clean kitchen towel. Let it rise in a warm place for 1-1.5 hours, or until doubled in size.
Step 5: While the dough is rising, prepare the Biscoff filling. In a small bowl, combine the softened unsalted butter, Biscoff cookie butter, light brown sugar, and ground cinnamon. Mix until well combined and creamy.
Step 6: Once the dough has doubled, gently punch it down to release the air. Turn the dough out onto a lightly floured surface. Using a rolling pin, roll the dough into a large rectangle, approximately 18×12 inches (45×30 cm) and about 1/4 inch thick.
Step 7: Evenly spread the Biscoff filling over the entire surface of the dough, leaving a small border (about 1/2 inch) on one of the longer sides.
Step 8: Starting from the longer side opposite the empty border, carefully roll the dough tightly into a log. Pinch the seam closed to secure the roll.
Step 9: Using a sharp knife or unflavored dental floss, cut the log into 12 equal pieces, each about 1.5 inches thick.
Step 10: Lightly grease a 9×13 inch baking dish. Arrange the cut cinnamon rolls in the prepared dish, leaving a little space between each as they will expand during the second rise.
Step 11: Cover the baking dish with plastic wrap or a clean kitchen towel and let the Biscoff Stuffed Cinnamon Rolls rise in a warm place for another 30-45 minutes, or until puffy and almost doubled in size.
Step 12: Preheat your oven to 375°F (190°C).
Step 13: Bake the Biscoff Stuffed Cinnamon Rolls for 20-25 minutes, or until golden brown on top and cooked through. If they start to brown too quickly, lightly tent them with aluminum foil.
Step 14: While the cinnamon rolls are baking, prepare the cream cheese glaze. In a medium bowl, whisk together the softened cream cheese, softened butter, powdered sugar, vanilla extract, and a tablespoon of milk (add more if needed to reach desired consistency). Beat until smooth and creamy.
Step 15: Once the Biscoff Stuffed Cinnamon Rolls are out of the oven, let them cool in the pan for 5-10 minutes before generously spreading the cream cheese glaze over the warm rolls. Serve immediately and enjoy!